Toxic Metabolites Research Articles

Toxins in plant pathogenesis: Understanding the role of toxins in host-pathogen interaction

The present-day concept of toxins in pathogenesis has acquired an important place in the arena of plant pathology. Because once the toxic metabolite of the pathogen is identified and characterized, it opens up many ways for combating the pathogen. Microbes use toxins as a weapon to cause damage and eventually destroy host cells. Plant pathogenic bacteria and fungi damage their host by producing diffusible toxins. These toxins induce several symptoms such as chlorosis, necrosis, water soaking, and wilting, which lead to the death of the plants. These toxins (secondary metabolites) are dangerous to the plants even in minute concentrations, and many of the toxins reproduce at least a few symptoms of relevant fungal or bacterial diseases. Plant pathogens use toxins as weapons to infect susceptible hosts. There has been significant progress in understanding these microbial toxins’ nature, structure, and their mode of action, which is discussed in this article. In addition to being employed to determine plant disease resistance, screening for disease-resistant mutants, and managing disease, studying pathogenic toxins and their underlying mechanisms for pathogenicity is crucial to understand the host-pathogen interactions.

Clinical Spectrum of Hereditary Tyrosinemia Type 1 in a Cohort of Pakistani Children.

Hereditary Tyrosinemia Type 1 (HT1), a rare autosomal recessive metabolic disorder, arises from fumarylacetoacetate (FAH) enzyme deficiency, resulting in toxic metabolite buildup. It manifests in acute, subacute, and chronic forms, with early diagnosis and Nitisinone treatment being vital. The study aims to highlight the different clinical presentations of Hereditary Tyrosinemia type 1 in a cohort of Pakistani children. Retrospective observational study. All patients diagnosed with HT1 at Shifa International Hospital, Islamabad and Pak Emirates Military Hospital, Rawalpindi between 2010 and 2023 were included. Information was collected regarding age, gender, symptoms, physical signs, and laboratory results. The study identified 6 cases of HT1. The average age at presentation was 8 months, with a mean delay in diagnosis of 26.8 months. Males were 4 (66.7%) and 2 (33.3%) were females. All patients had underlying liver disease presenting as abdominal distension with hepatosplenomegaly and accompanying growth failure. Four cases presented with rickets, 2 of which had hypophosphatemic rickets. Urine for succinylacetone was raised in all patients. Alpha fetoprotein was raised but hepatocellular carcinoma was diagnosed in 1 patient only. Low protein diet, and vitamin supplements were used for management. Five of the 6 patients died within 2 years of diagnosis. Delayed referrals and unavailability of Nitisinone are the major challenges in diagnosing and treating HT1 in Pakistan.

Untargeted Metabolomics to Investigate the Influence of Epigenetic Modifiers on the Metabolism of Fusarium verticillioides.

Toxigenic fungi are capable of producing toxic metabolites, called mycotoxins. But the presence of silent and lowly expressed genes represents the main challenge for the discovery of novel mycotoxins, especially their lesser-known forms, commonly referred to as "emerging mycotoxins." Epigenetic modifiers (EMs) are compounds that are able to alter the production of metabolites through the induction of silent biosynthetic pathways leading to an enhanced chemical diversity. The aim of this study was to assess the effects of different chemical modulators on the metabolic profiles of the well-known toxigenic fungal species, Fusarium verticillioides. Four EMs, 5-azacytidine, sodium butyrate, nicotinamide (NIC), and sodium valproate (SV), were used. Following their addition to Fusarium verticillioides cultures, the metabolic profiles were analyzed by using UHPLC-HRMS/MS under targeted and untargeted metabolomics approaches. Metabolites were putatively annotated through the use of MS-DIAL and MS-FINDER. Our results show that the treatment with SV induced the most important alteration of the secondary metabolic profile of F. verticillioides, by promoting the expression of cryptic genes. Among the 50 most discriminating metabolites across five culture conditions, 12 were fusarins or fusarin analogs. In contrast, SB and NIC had little impact on these metabolites. The study highlights SV's ability to alter gene expression by inhibiting DNA deacetylation in fungal strains. This research could have significant implications for agriculture and food industry, especially in regions facing major mycotoxin challenges.

Comparison of microbial communities and the profile of sulfate-reducing bacteria in patients with ulcerative colitis and their association with bowel diseases: a pilot study.

Considerable evidence has accumulated regarding the molecular relationship between gut microbiota (GM) composition and the onset (clinical presentation and prognosis of ulcerative colitis (UC)). In addition, it is well documented that short-chain fatty acid (SCFA)-producing bacteria may play a fundamental role in maintaining an anti-inflammatory intestinal homeostasis, but sulfate- and sulfite reducing bacteria may be responsible for the production of toxic metabolites, such as hydrogen sulfide and acetate. Hence, the present study aimed to assess the GM composition - focusing on sulfate-reducing bacteria (SRB) - in patients with severe, severe-active and moderate UC. Each one of the six enrolled patients provided two stool samples in the following way: one sample was cultivated in a modified SRB-medium before 16S rRNA sequencing and the other was not cultivated. Comparative phylogenetic analysis was conducted on each sample. Percentage of detected gut microbial genera showed considerable variation based on the patients' disease severity and cultivation in the SRB medium. In detail, samples without cultivation from patients with moderate UC showed a high abundance of the genera Bacteroides, Bifidobacterium and Ruminococcus, but after SRB cultivation, the dominant genera were Bacteroides, Klebsiella and Bilophila. On the other hand, before SRB cultivation, the main represented genera in patients with severe UC were Escherichia-Shigella, Proteus, Methanothermobacter and Methanobacterium. However, after incubation in the SRB medium Bacteroides, Proteus, Alistipes and Lachnoclostridium were predominant. Information regarding GM compositional changes in UC patients may aid the development of novel therapeutic strategies (e.g., probiotic preparations containing specific bacterial strains) to counteract the mechanisms of virulence of harmful bacteria and the subsequent inflammatory response that is closely related to the pathogenesis of inflammatory bowel diseases.

Entomopathogenic Fungi: Nature's Secret Weapon Against Agricultural Pests

Insect pests pose significant challenges to agricultural productivity and crop yield worldwide. Conventional pest control methods, such as chemical pesticides, have limitations and adverse environmental effects. Therefore, there is a growing need for sustainable and eco-friendly alternatives in pest management. This review explores the potential of entomopathogenic fungi as a promising biological control agent for insect pests in agriculture. The review begins by providing an overview of entomopathogenic fungi and their significancce. These fungi possess unique mechanisms to infect and kill insect pests. The mode of action involves attachment of fungal spores to the insect's cuticle, followed by penetration, colonization, and release of toxic metabolites within the host. Various factors influence the efficacy of entomopathogenic fungi, including environmental conditions, insect host susceptibility, and formulation/application methods. The benefits of entomopathogenic fungi as biological control agents are discussed, including their compatibility with integrated pest management (IPM) strategies and minimal impact on non-target organisms. However, challenges exist in scaling up their commercial application. The review presents case studies showcasing successful field applications of entomopathogenic fungi in pest management. Future prospects and research directions are identified, emphasizing the importance of continued advancements in understanding the interactions between entomopathogenic fungi and insect pests. Regulatory frameworks and public acceptance are crucial for the widespread adoption of these fungi in agriculture. In conclusion, entomopathogenic fungi offer immense potential as sustainable and effective tools for biological control of insect pests in agriculture. Their ability to target specific pests, compatibility with IPM, and minimal environmental impact make them a viable alternative to chemical pesticides. Further research, collaboration, and implementation are necessary to fully harness the potential of entomopathogenic fungi in integrated pest management strategies.

ZmB12D, a target of transcription factor ZmWRKY70, enhances the tolerance of Arabidopsis to submergence

Submergence stress represents a serious threat to the yield and quality of maize because it can lead to oxygen deficiency and the accumulation of toxic metabolites. However, the mechanisms by which maize resists the adverse effects of submergence stress have yet to be fully elucidated. Here, we cloned a gene from maize Balem (Barley aleurone and embryo), ZmB12D, which was expressed at significant levels in seed embryos during imbibition and in leaves under submergence stress. Subcellular localization analysis indicated that the ZmB12D protein was localized in the mitochondria. The overexpression of ZmB12D in increased the tolerance of Arabidopsis to submergence stress, probably due to a reduction in the levels of malonaldehyde (MDA), the increased activity of antioxidant enzymes (SOD, POD and CAT), enhanced electron transport by coordinating the expression of non-symbiotic hemoglobin-2 (AHb2) and Fe transport-related (AtNAS3) genes (mediating Fe and oxygen availability) and also modulated the anaerobic respiration rates through upregulated the AtPDC1, AtADH1, AtSUS4 genes under submergence. Yeast one-hybrid (Y1H) and transient transactivation assays demonstrated that ZmWRKY70 bound to the ZmB12D promoter and activated ZmB12D. Collectively, out findings indicate that ZmB12D plays an important role in the tolerance of maize to submergence stress. This research provides new insights into the genetic improvement of maize with regards to submergence tolerance.

POTENTIAL OF DIFFERENT MYCOTOXIN ADSORBENTS UNDER IN VITRO CONDITIONS

Mycotoxins are a large and chemically diverse group of toxic secondary metabolites. Regarding their prevalence in animal feed and the effect on animal health, the biggest problems in terms of safety and economic losses are caused by aflatoxins, fumonisins, ochratoxins, trichothecenes and zearalenone. Adsorbents are substances that are added to food contaminated with mycotoxins, in order to bind them in the gastrointestinal tract and thereby prevent or reduce their effect. The aim of this study was to examine the possibility of using pyrophyllite as a mineral adsorbent, as well as preparations made of ground peach pits of different particle sizes as organic adsorbents, for adsorption of deoxynivalenol and ochratoxin A. Mycotoxin adsorption experiments were performed in vitro in electrolyte solutions at pH 3 and 7. The adsorption efficiency of the adsorbent was expressed as adsorption index. Pyrophyllite had adsorption index ​​of 13.47% for ochratoxin A at pH 3, while at pH 7, as well as for deoxynivalenol, the same mycotoxin produced a negligible degree of adsorption. Ground peach stones (of larger diameter, d = 0.1 mm) had considerable adsorption rates for ochratoxin A at pH 3 (34.41%) and deoxynivalenol at pH 7 (18.57%). The values were similar for smaller diameter (d < 0.1 mm) for ochratoxin A at pH 3 (42.71%) and deoxynivalenol at pH 7 (20.11%). The obtained results suggest that the potential of the preparation of ground peach stones for the adsorption of tested mycotoxins is higher compared to the potential of pyrophyllite, but there are differences in their efficiency depending on the pH value of the adsorption environment.

Evaluation of Safety and Probiotic Traits from a Comprehensive Genome-Based In Silico Analysis of Ligilactobacillus salivarius P1CEA3, Isolated from Pigs and Producer of Nisin S.

Ligilactobacillus salivarius is an important member of the porcine gastrointestinal tract (GIT). Some L. salivarius strains are considered to have a beneficial effect on the host by exerting different probiotic properties, including the production of antimicrobial peptides which help maintain a healthy gut microbiota. L. salivarius P1CEA3, a porcine isolated strain, was first selected and identified by its antimicrobial activity against a broad range of pathogenic bacteria due to the production of the novel bacteriocin nisin S. The assembled L. salivarius P1CEA3 genome includes a circular chromosome, a megaplasmid (pMP1CEA3) encoding the nisin S gene cluster, and two small plasmids. A comprehensive genome-based in silico analysis of the L. salivarius P1CEA3 genome reveals the presence of genes related to probiotic features such as bacteriocin synthesis, regulation and production, adhesion and aggregation, the production of lactic acid, amino acids metabolism, vitamin biosynthesis, and tolerance to temperature, acid, bile salts and osmotic and oxidative stress. Furthermore, the strain is absent of risk-related genes for acquired antibiotic resistance traits, virulence factors, toxic metabolites and detrimental metabolic or enzymatic activities. Resistance to common antibiotics and gelatinase and hemolytic activities have been discarded by in vitro experiments. This study identifies several probiotic and safety traits of L. salivarius P1CEA3 and suggests its potential as a promising probiotic in swine production.

Simultaneous Determination of Trichothecenes and Zearalenone in Food by Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry (UPLC-MS/MS)

Trichothecenes (deoxynivalenol, 3- and 15-acetyl-deoxynivalenol) and zearalenone are toxic secondary metabolites produced by Fusarium species. Although managing these mycotoxins simultaneously is crucial, current analytical methods differ because of their distinct properties. In this study, food matrix extraction conditions were established and applied to cereal-based foods (n = 90). The optimal conditions were developed by utilizing fragment ions and precursors, following the guidelines established by the Association of Official Agricultural Chemists (AOAC). The developed method demonstrated high accuracy and reliability within 20 min, even for samples with low concentrations. Consequently, the recovery range of the fat-oil-processed products and cereal sirup improved from 27.0% to 98.3% and 27.6% to 97.8%, respectively. This improved extraction method offers a more convenient and rapid approach for the analysis of various matrices. Furthermore, these optimized methods can be extended to monitor the co-occurrence of mycotoxins in cereal-based foods, providing valuable assistance to the food industry and regulatory agencies for detecting and monitoring mycotoxins that may pose potential health risks.

Creating large chromosomal segment deletions in Aspergillus flavus by a dual CRISPR/Cas9 system: Deletion of gene clusters for production of aflatoxin, cyclopiazonic acid, and ustiloxin B

Aspergillus flavus produces hepatocarcinogenic aflatoxin that adversely impacts human and animal health and international trade. A promising means to manage preharvest aflatoxin contamination of crops is biological control, which employs non-aflatoxigenic A. flavus isolates possessing defective aflatoxin gene clusters to outcompete field toxigenic populations. However, these isolates often produce other toxic metabolites. The CRISPR/Cas9 technology has greatly advanced genome editing and gene functional studies. Its use in deleting large chromosomal segments of filamentous fungi is rarely reported. A system of dual CRISPR/Cas9 combined with a 60-nucleotide donor DNA that allowed removal of A. flavus gene clusters involved in production of harmful specialized metabolites was established. It efficiently deleted a 102-kb segment containing both aflatoxin and cyclopiazonic acid gene clusters from toxigenic A. flavus morphotypes, L-type and S-type. It further deleted the 27-kb ustiloxin B gene cluster of a resulting L-type mutant. Overall efficiencies of deletion ranged from 66.6 % to 85.6 % and efficiencies of deletions repaired by a single copy of donor DNA ranged from 50.5 % to 72.7 %. To determine the capacity of this technique, a pigment-screening setup based on absence of aspergillic acid gene cluster was devised. Chromosomal segments of 201 kb and 301 kb were deleted with efficiencies of 57.7 % to 69.2 %, respectively. This system used natural A. flavus isolates as recipients, eliminated a forced-recycling step to produce recipients for next round deletion, and generated maker-free deletants with sequences predefined by donor DNA. The research provides a method for creating genuine atoxigenic biocontrol strains friendly for field trial release.

Composition and Diversity of the Endobacteria and Ectobacteria of the Invasive Bark Beetle Hylurgus ligniperda (Fabricius) (Curculionidae: Scolytinae) in Newly Colonized Areas.

Hylurgus ligniperda (Fabricius) (Curculionidae: Scolytinae) is a new invasive pest beetle in China, which colonized the Shandong province, causing devastating damage. Originating in Europe, it has spread to Oceania, Asia, North and South America. Bacterial associates have been frequently reported to play a vital role in strengthening the ecological adaptations of bark and ambrosia beetles. The environmental adaptability of H. ligniperda may be supported by their associated bacteria. Bacterial communities colonizing different body parts of insects may have different functions. However, little is known about the bacteria associated with H. ligniperda and their potential involvement in facilitating the adaptation and invasion of the beetles into new environments. In this study, we employed high-throughput sequencing technology to analyze the bacterial communities associated with male and female adults of H. ligniperda by comparing those colonizing the elytra, prothorax, and gut. Results showed that the bacterial communities of male and female adults were similar, and the elytra samples had the highest bacterial diversity and richness, followed by the gut, while the prothorax had the lowest. The dominant phyla were Proteobacteria, Firmicutes, and Actinobacteriota, while the dominant genera were Serratia, Lactococcus, Rhodococcus, unclassified Enterobacteriaceae, and Gordonia. Among these, Rhodococcus and Gordonia were the specific genera of endobacteria and ectobacteria, respectively. Differences in the distribution of associated bacteria may suggest that they have different ecological functions for H. ligniperda. The results of functional prediction showed that bacteria were enriched in terpenoid backbone biosynthesis, degradation of aromatic compounds, limonene and pinene degradation, neomycin, kanamycin and gentamicin biosynthesis, indicating that they may assist their beetles in synthesizing pheromones, degrading toxic secondary metabolites of host trees, and antagonizing pathogenic fungi. These results help us understand the interaction between H. ligniperda and bacteria and highlight possible contributions to the invasion process.

Hemoadsorption Therapy for Critically Ill Patients with Acute Liver Dysfunction: A Meta-Analysis and Systematic Review.

Critically ill patients are at risk of developing acute liver dysfunction as part of multiorgan failure sequelae. Clearing the blood from toxic liver-related metabolites and cytokines could prevent further organ damage. Despite the increasing use of hemoadsorption for this purpose, evidence of its efficacy is lacking. Therefore, we conducted this systematic review and meta-analysis to assess the evidence on clinical outcomes following hemoadsorption therapy. A systematic search conducted in six electronic databases (PROSPERO registration: CRD42022286213) yielded 30 eligible publications between 2011 and 2023, reporting the use of hemoadsorption for a total of 335 patients presenting with liver dysfunction related to acute critical illness. Of those, 26 are case presentations (n = 84), 3 are observational studies (n = 142), and 1 is a registry analysis (n = 109). Analysis of data from individual cases showed a significant reduction in levels of aspartate transaminase (p = 0.03) and vasopressor need (p = 0.03) and a tendency to lower levels of total bilirubin, alanine transaminase, C-reactive protein, and creatinine. Pooled data showed a significant reduction in total bilirubin (mean difference of -4.79 mg/dL (95% CI: -6.25; -3.33), p = 0.002). The use of hemoadsorption for critically ill patients with acute liver dysfunction or failure seems to be safe and yields a trend towards improved liver function after therapy, but more high-quality evidence is crucially needed.

Long-term effects of oil contamination on soil quality and metabolic function.

Widespread soil contamination with oil and the toxicity of petroleum hydrocarbons to soil biota make it extremely important to study microbial responses to oil stress. Soil metabolites reflect the main metabolic pathways in the soil microbial community. The examination of changes in the soil metabolic profile and metabolic function is essential for a better understanding of the nature of the pollution and restoration of the disturbed soils. The present study aimed to assess the long-term effect of oil on the ecological state of the soil, evaluate quantitative and qualitative differences in metabolite composition between soil contaminated with oil and non-contaminated soil, and reveal biologically active metabolites that are related to oil contamination and can be used for contamination assessment. A long-term field experiment was conducted to examine the effects of various oil concentrations on the biochemical properties and metabolic profile of the soil. Podzolic soil contaminated with oil demonstrated the long-term inhibition of soil biological activity and vegetation. Oil affected the metabolic activity of soil fungi increasing the production of toxic metabolites. A metabolomic approach was employed to determine soil metabolites. The metabolite profile was found to vary greatly between oil-contaminated and non-contaminated soils. Carbohydrates had the largest number of metabolites negatively affected by oil, while the content of organic acids, phenolic compounds, and terpenoids was mainly increased in oil-contaminated soil. The evaluation of the long-term impact of oil on microbial metabolism can make a valuable contribution to the assessment of soil quality and the activity of soil microorganisms being under stress from oil pollution. The results contribute to a further understanding of the role of microorganisms in the ecological functions of contaminated soil, which can be useful in the development of rehabilitation strategies for disturbed sites.

Heart Diseases in Patients with Organic Acidemia

Objective: Organic acidemias are intoxication-type inborn errors of the metabolism with multiple organ involvement. Patients with organic acidemia usually present in the neonatal or infantile period with high anion gap metabolic acidosis and hyperammonemia. The present study investigates the presence of congenital heart defects and secondary heart diseases in patients with organic acidemia. Material and Methods: Included in the study were 31 patients of whom 14 were diagnosed with methylmalonic acidemia (MMA), 11 with propionic acidemia and six with isovaleric acidemia. The cardiac findings of all patients included in the study were evaluated. Results: Of the sample, 63.64% were identified with accompanying congenital heart disease, with the most common diagnosis being propionic acidemia and the most common heart defects being atrial septal defects and mitral regurgitation. Conclusion: The accumulation of toxic intermediate metabolites due to enzyme deficiency is thought to be the main mechanism behind the cardiac involvement noted in organic acidemias. In the presence of unexplained deterioration, the potential for organic acidemia to accompany congenital heart disease should be kept in mind, and so it is important to screen patients with organic acidemias by echocardiography.

Quantitative risk ranking of mycotoxins in milk under climate change scenarios

Mycotoxins are toxic fungal metabolites that may occur in crops. Mycotoxins may carry-over into bovine milk if bovines ingest mycotoxin-contaminated feed. Due to climate change, there may be a potential increase in the prevalence and concentration of mycotoxins in crops. However, the toxicity to humans and the carry-over rate of mycotoxins from feed to milk from bovines varies considerably. This research aimed to rank emerging and existing mycotoxins under different climate change scenarios based on their occurrence in milk and their toxicity to humans. The quantitative risk ranking took a probabilistic approach, using Monte-Carlo simulation to take account of input uncertainties and variabilities. Mycotoxins were ranked based on their hazard quotient, calculated using estimated daily intake and tolerable daily intake values. Four climate change scenarios were assessed, including an Irish baseline model in addition to best-case, worst-case, and most likely scenarios, corresponding to equivalent Intergovernmental Panel on Climate Change (IPCC) scenarios. This research prioritised aflatoxin B1, zearalenone, and T-2 and HT-2 toxin as potential human health hazards for adults and children compared to other mycotoxins under all scenarios. Relatively lower risks were found to be associated with mycophenolic acid, enniatins, and deoxynivalenol. Overall, the carry-over rate of mycotoxins, the milk consumption, and the concentration of mycotoxins in silage, maize, and wheat were found to be the most sensitive parameters (positively correlated) of this probabilistic model. Though climate change may impact mycotoxin prevalence and concentration in crops, the carry-over rate notably affects the final concentration of mycotoxin in milk to a greater extent. The results obtained in this study facilitate the identification of risk reduction measures to limit mycotoxin contamination of dairy products, considering potential climate change influences.

Proficient sonophotocatalytic degradation of organic pollutants using Co3O4/TiO2 nanocomposite immobilized on zeolite: Optimization, and artificial neural network modeling

The health of all living organisms is greatly influenced by the quality of the water. Therefore, developing cost-effective, eco-friendly, and easily accessible methods is desperately needed to meet the high global demand for clean water. Recently, nanozyme-based dye degradation methods have been promising for the remediation of water pollution. In this work, peroxidase-mimic Co3O4/TiO2 nanocomposite was synthesized and characterized for its size, morphology, and crystalline structure. Colorimetric assay results showed that the peroxidase-like activity of the Co3O4/TiO2 nanocomposite was considerably enhanced compared to the pure Co3O4 NPs and TiO2 NPs. Besides excellent enzyme-mimic activity, the higher sonophotocatalytic dye degradation capability of the nanocomposite after immobilization on zeolite (Co3O4/TiO2@Ze) was also demonstrated. Under optimal conditions (pH = 5.0, 25 °C), 0.1 g/L of catalyst was able to degrade 100 % of methylene blue (MB) with 600 μM in the presence of 30 μM H2O2 within 12 min. GC/MS analysis and toxicity studies revealed less toxic metabolite production after treatment of MB with sonophotocatalytic Co3O4/TiO2@Ze. Modeling of MB degradation using artificial neural networks (ANN) with a 5:6:1 topology was successfully performed, and the results confirmed the fitness of theoretical and experimental outputs according to the calculated correlation coefficient values. The prepared nanocomposite could thus be used as a promising and highly effective catalyst for the removal of organic dyes from polluted water.

Determination of the toxic metabolite aflatoxin M1 in raw, pasteurized and ultra-pasteurized milks comparing the ELISA Technique and High Performance Liquid Chromatography.

Aflatoxins are very potent toxic metabolites with carcinogenic, teratogenic, mutagenic, hepatotoxic and immunosuppressive effects, which constitute a potential risk to human health, so they should be considered as a latent problem that requires continuous examination in order to ensure food quality. This study was carried out with the objective of quantitatively determining the content of Aflatoxin M1 in three types of raw, pasteurized and ultrapasteurized milk consumed in the city of Cuenca-Ecuador, through thecomparative analysis of the High Performance Liquid Chromatography HPLC Techniques, after an extraction process in immunoaffinity columns and the ELISA Technique. Eighty-four samples were analyzed in three types of milk: raw, pasteurized and ultra-pasteurized, with the ELISA technique, none exceeded the detection limit of Aflatoxin M1(125 ppt or 0.125 ppb), established both by the national INEN: 9-10 in force and the parameters established by the Food and Agriculture Organization of the United Nations, Food and Drug Administration of the United States (0.5ppb) and with the High Performance Liquid Chromatography technique, 16 positive samples were found that were between the limit of detection and quantification (0.09 - 0.18 ppb.), obtaining a prevalenceof 19%, so that the High Performance Liquid Chromatography technique is more sensitive in the quantitative detection of the toxic metabolite Aflatoxin M1 in milk.

Structural Elucidation of Agrochemical Metabolic Transformation Products Based on Infrared Ion Spectroscopy to Improve In Silico Toxicity Assessment.

Toxicological assessments of newly developed agrochemical agents consider chemical modifications and their metabolic and biotransformation products. To carry out an in silico hazard assessment, understanding the type of chemical modification and its location on the original compound can greatly enhance the reliability of the evaluation. Here, we present and apply a method based on liquid chromatography-mass spectrometry (LC-MS) enhanced with infrared ion spectroscopy (IRIS) to better delineate the molecular structures of transformation products before in silico toxicology evaluation. IRIS facilitates the recording of IR spectra directly in the mass spectrometer for features selected by retention time and mass-to-charge ratio. By utilizing quantum-chemically predicted IR spectra for candidate molecular structures, one can either derive the actual structure or significantly reduce the number of (isomeric) candidate structures. This approach can assist in making informed decisions. We apply this method to a plant growth stimulant, digeraniol sinapoyl malate (DGSM), that is currently under development. Incubation of the compound in Caco-2 and HepaRG cell lines in multiwell plates and analysis by LC-MS reveals oxidation, glucuronidation, and sulfonation metabolic products, whose structures were elucidated by IRIS and used as input for an in silico toxicology assessment. The toxicity of isomeric metabolites predicted by in silico tools was also assessed, which revealed that assigning the right metabolite structure is an important step in the overall toxicity assessment of the agrochemical. We believe this identification approach can be advantageous when specific isomers are significantly more hazardous than others and can help better understand metabolic pathways.

Sensitivity of Human Induced Pluripotent Stem Cells and Thereof Differentiated Kidney Proximal Tubular Cells towards Selected Nephrotoxins.

Proximal tubular epithelial cells (PTEC) are constantly exposed to potentially toxic metabolites and xenobiotics. The regenerative potential of the kidney enables the replacement of damaged cells either via the differentiation of stem cells or the re-acquisition of proliferative properties of the PTEC. Nevertheless, it is known that renal function declines, suggesting that the deteriorated cells are not replaced by fully functional cells. To understand the possible causes of this loss of kidney cell function, it is crucial to understand the role of toxins during the regeneration process. Therefore, we investigated the sensitivity and function of human induced pluripotent stem cells (hiPSC), hiPSC differentiating, and hiPSC differentiated into proximal tubular epithelial-like cells (PTELC) to known nephrotoxins. hiPSC were differentiated into PTELC, which exhibited similar morphology to PTEC, expressed prototypical PTEC markers, and were able to undergo albumin endocytosis. When treated with two nephrotoxins, hiPSC and differentiating hiPSC were more sensitive to cisplatin than differentiated PTELC, whereas all stages were equally sensitive to cyclosporin A. Both toxins also had an inhibitory effect on albumin uptake. Our results suggest a high sensitivity of differentiating cells towards toxins, which could have an unfavorable effect on regenerative processes. To study this, our model of hiPSC differentiating into PTELC appears suitable.

The influence of acetaminophen on human health

In pain management, acetaminophen, a widely used analgesic and antipyretic, holds a central position. The metabolic pathways can lead to acetaminophen-induced hepatotoxicity, elucidating from glucuronidation to the cytochrome P450 system. It meticulously details the complexities of acetaminophen metabolism, culminating in the formation of the toxic metabolite, n-acetyl-p-benzoquinone imine (NAPQI). Providing a holistic understanding guiding clinical practice, it explores risk factors, clinical implications, and management strategies. Transitioning to respiratory risks, potential associations between acetaminophen use and asthma, rhinoconjunctivitis, and eczema in adolescents is investigated. The study offers nuanced insights, urging caution in acetaminophen use during adolescence. In addition, the role of drug metabolism in acetaminophen-induced hepatic necrosis is also analyzed. Despite its temporal origins, the studys identification of cytochrome P450 as a catalyst for NAPQI formation remains foundational, contributing mechanistic insights to drug-induced liver injury knowledge. Synthesizing these studies reveals a delicate balance between acetaminophen metabolism and detoxification, crucial in determining its hepatotoxic potential. This nuanced understanding informs clinical practice and beckons researchers to bridge gaps, embarking on further explorations. In essence, this synthesis becomes a compass guiding the scientific community toward a profound comprehension of acetaminophen, epitomizing the standards expected in high-quality, peer-reviewed literature.